This is likely due to xTool jank fixed in 2.0:
- XTool gcode output in mm only (#621)
IIRC, xTool’s G-Code interpreter ignores G20 and knows you really meant to use millimeters, because nobody uses inches these days. LightBurn emits the correct G-Code and xTool fumbles the ball.
If running 2.0 RC5 fixes the problem, that was the problem.